If you get exhausted and you use a bears endurance potion, and your exhau treshold increases, your exhau will be bugged, untill you log off or rest.
As in, even when it lowers under the treshold the exhaustion will remain as an effect on you.
I was fighting enemies, and was nearing exhaustion, so i drank a potion, however i miscalculated and i drank the potion after the exhaustion roll was done. So my character was exhausted, but when i drank the potion and my constitution score got raised by 4 points, i should have been again under the treshold, however no such thing happened.
Thereafter i managed to defeat the enemy while under exhau, and i waited for my exhau to drop to near 0. But the exhaustion effect never faded untill i have rested with my character.